This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The Epithelial Electrophysiology Core provides the instrumentation, expertise, training and mentoring in epithelial electrophysiology necessary for COBRE projects. COBRE and KSU projects use Core resources to make non-invasive current and non-radioactive ion flux measurements. The facility supports a vibrating current-density probe and self-referencing ion-selective electrodes, and provides technical support to investigators.